Proving low-pressure liquid CO₂ handling at commercial scale
“ACTIVE completes the first large-scale low-pressure CO₂ gas-trial campaign, demonstrating the safe operation and installed performance of Babcock LGE’s ecoCO2® cargo-handling system.”
Carbon capture projects will depend on a safe, efficient and scalable means of transporting captured CO₂ from emitters to storage locations.
As this emerging value chain develops, shipowners also require flexibility. Dedicated LCO₂ trades are not yet mature in every market, so an asset capable of carrying other liquefied gases can help protect its commercial value during this transitional period.
Capital Clean Energy Carriers’ ACTIVE, the first of four 22,000 m³ low-pressure LCO₂ multi-gas carriers, was developed to meet both requirements. Built by HD Hyundai Mipo, the vessel combines commercial-scale low-pressure CO₂ transportation with flexibility to carry LPG, ammonia and selected petrochemical cargoes.
At the heart of the vessel is Babcock LGE’s ecoCO₂® cargo-handling system, with its first large-scale CO₂ gas trial providing the critical step from engineering design and approval to demonstrated operation onboard a commercial vessel.
The challenge
Carrying LCO₂ cargo at scale
Liquid CO₂ presents a distinct phase-management challenge. Its operating pressure and temperature must be carefully controlled to prevent the cargo approaching its triple-point region, where solid CO₂ can form and affect equipment, pipework and cargo operations.
For ACTIVE, the cargo system was developed around low-pressure tank design conditions of approximately 8.0 barg and -55°C. This required coordinated control of tank pressure, cargo temperature, vapour handling, reliquefaction and cargo transfer throughout loading, storage and discharge operations.
For the shipowner and shipyard, maintaining this operating envelope is more than a process requirement. It is fundamental to cargo availability, system reliability and confidence that the vessel can serve the emerging CO2 transport market.
The project also required a genuine multi-gas design. Equipment selection, material compatibility, process segregation, control philosophy, relief and venting arrangements, and operating procedures all had to account for the different properties and operating requirements of LCO₂ and the vessel’s other approved cargoes (LPG, ammonia, butadiene – to name only a few of the extensive cargo list).
This was therefore more than the adaptation of a conventional LPG cargo system. It required a purpose-engineered solution capable of safely managing low-pressure CO₂ while retaining the vessel flexibility to carry other cargoes that is needed to generate commercial returns while the carbon capture and storage market develops.
Our customer requirement
HD Hyundai Mipo contracted Babcock LGE to provide the cargo-handling system for a series of four 22,000 m³ low-pressure LCO₂ multi-gas carriers being built for Capital Clean Energy Carriers.
Before delivery of the first vessel, HD Hyundai Mipo needed to demonstrate that the complete LCO₂ cargo plant met the agreed functional and performance requirements. Capital Clean Energy Carriers, as the shipowner and end user, was closely involved throughout the project to ensure the system also addressed its operational requirements.
The gas trial covered the complete low-pressure CO₂ operating sequence, from tank preparation, pressurisation and cooldown through to liquid loading, reliquefaction, cargo transfer, stripping, warming and controlled depressurisation. It also demonstrated Babcock LGE’s bespoke Cargo Control System and supported crew familiarisation and training.
Babcock LGE developed the trial programme and target figures and supported HD Hyundai Mipo during execution. The results were reviewed with involvement from HD Hyundai Mipo, Capital Clean Energy Carriers and Lloyd’s Register (Classification Society), providing practical evidence that the installed cargo plant operated safely and achieved its intended performance.
What Babcock LGE delivered
Babcock LGE provided HD Hyundai Mipo with a fully integrated multi-gas cargo-handling package, including:
Reliquefaction and vapour-management systems
Cargo pumps and CO₂ vaporisation
Cargo Control System
Process, control and safety philosophies
Engineering and procurement
Commissioning and gas-trial support
Crew familiarisation and training
This combined in-house engineering with the procurement and management of the wider cargo-system package, giving HD Hyundai Mipo a coordinated solution for the safe handling of low-pressure LCO₂ and other approved cargoes.
Designed for the wider CCS value chain
ecoCO₂® is designed to address the differing requirements of CCS projects, including vessel size, tank geometry, design pressure, shipping profile, cargo composition and loading and discharge-terminal conditions. Its flexible design uses standardised, field-proven equipment where appropriate to support reliability, maintainability and system integrity.
The product proposition is built around five customer benefits:
Controlled low-pressure LCO₂ handling
Multi-cargo trading flexibility
Integrated system responsibility across the cargo handling package
Standardised, field-proven equipment where appropriate
A repeatable platform for a four-vessel programme
For the owner, this flexibility can help reduce exposure during the early development of the LCO₂ market. ACTIVE entered initial service carrying LPG, demonstrating the commercial relevance of its multi-gas design, although the first LPG operation was subject to a separate gas trial covering the LPG-specific equipment and procedures not included in the CO₂ campaign
From engineering design to operational proof
A first-of-kind trial campaign
The first CO₂ gas-trial campaign represented the point at which the engineering had to prove itself onboard.
The complete gas-trial programme ran from 30 October to 5 December 2025, including early tank drying and inerting activities. The principal CO₂ cargo operations took place from 18 November to 5 December 2025 at HD Hyundai Mipo.
Unlike a conventional terminal loading operation, the trial cargo had to be transported to the yard by road tanker. More than 54 truckloads of domestically sourced CO₂ supported the campaign, with approximately 533 tonnes of liquid CO₂ ultimately delivered to the vessel. Loading took place at an average rate of approximately 10 tonnes per hour, with two reliquefaction units operating.
The use of road tankers extended the trial duration, but allowed the teams to perform a comprehensive, methodical validation of the cargo tanks, cargo-management systems and installed equipment.
Proving control at the phase boundary
The purpose of the gas trial was not simply to operate individual items of equipment. It was to demonstrate that the complete ecoCO₂ system worked as an integrated cargo plant.
Throughout the campaign, the system successfully maintained control of the LCO₂ cargo within its required pressure and temperature boundaries. The cargo tanks were prepared and cooled, liquid CO₂ was loaded and managed onboard, boil-off gas was handled through the reliquefaction system, and cargo-transfer operations were completed under controlled conditions.
The trial verified the operation of the principal elements of the cargo-handling system, including:
Cargo tank preparation and conditioning
Controlled management of the CO₂ phase boundary
Loading and storage of low-pressure LCO₂
Boil-off gas management and reliquefaction
Cargo circulation and transfer
Cargo Control System functionality
Safe warming and depressurisation of the system
Crew familiarisation with the operating procedures
Successful completion of this sequence demonstrated that ecoCO₂ could safely manage low-pressure liquid CO₂ onboard a commercial-scale carrier as a complete, integrated system.
Successful delivery for the customer
For HD Hyundai Mipo, the successful gas trial provided practical evidence that the cargo-handling system supplied by Babcock LGE met the functional requirements of the first vessel.
For Capital Clean Energy Carriers, as shipowner and end user, it demonstrated that the vessel could safely load, control and handle low-pressure LCO₂ while providing the multi-cargo flexibility needed as dedicated CO₂ shipping trades develop.
Following the trial, Babcock LGE continued to support the shipyard and shipowner and through the final delivery phase. This included responding to shipowner feedback and accommodating additional operational preferences ahead of vessel delivery on 5th January 2026.
ACTIVE demonstrates that the low-pressure LCO2 handling can move beyond design and approval into repeatable commercial operation.
For HD Hyundai Mipo, the first vessel established a proven basis for the remaining series. For Capital Clean Energy Carriers, it provides a vessel capable of entering the emerging CO2 while retaining trading flexibility in established gas markets.
First of a kind engineering has become a platform for repeatable delivery.
ACTIVE was the first vessel in a series of four. Following the successful first gas trial and delivery:
- The second vessel was delivered in April 2026
- The third vessel entered gas trials in August 2026
- The fourth and final vessel is scheduled for delivery later in 2026
Lessons from the first vessel, including owner operational preferences and requested refinements, have been incorporated into the sister-vessel programme.
The first-of-kind engineering and validation work creates a proven foundation for the remaining vessels, reducing uncertainty and supporting more efficient commissioning and delivery across the series.
